There's a singular set of first memories that many of us share of our first experience with a home computer. The satisfying give of the keys on the black, cumbersome keyboard; a constantly whirring cassette tape, or pleasingly tactile floppy disk; the jarringly vivid palette of sprites and characters burning their way out of the shiny abyss, and an array of otherworldly, synthesised sounds not yet familiar to our untrained ears.

Whether sheathed in an ungainly dustcover at the back of a classroom or secreted away in your friend's brother's basement, it's more than likely that these formative experiences were taking place on a BBC Micro or ZX Spectrum. In an age of iPhones and Windows, the ubiquity of these machines during the early 1980s and the indelible mark they etched on a generation is all but too easy to forget.

Micro Men, screening on BBC4 tonight, follows the stories of the two men briefly catapulted to the forefront of the computer industry by these new-fangled "personal computers". It attempts to explain how Clive Sinclair and Chris Curry, played in the film by Alexander Armstrong and Martin Freeman, managed, for a couple of years at least, to divert the world's gaze away from the Silicon Valley and towards a couple of small, unglamorous East Anglian tech companies.

Clive Sinclair (now Sir Clive to you and me) was, by 1978, established as an inventor and businessman with his company Sinclair Radionics. Clashes with his government backers led him to set up shop with one of his most talented employees, Chris Curry. While Sinclair's interests had until this point revolved around smaller gadgets like pocket televisions and calculators – along with his longstanding dream of pioneering the electric car – the two men were quick to see the potential in the growing home computers industry.

Their first product, developed by Curry, was the MK14, a basic computer kit released to satisfy the growing interest in personal computing. It sold out immediately. However, disagreements over future projects and Sinclair's legendary temper (which makes frequent appearances in Micro Men) meant this was their last joint venture.

The two men parted ways acrimoniously – Curry branching out on his own to form the company that would become Acorn Computers. Backed by entrepreneur and then Cambridge student Hermann Hauser (a charming fop in the film) Curry set about raiding Cambridge University of its most talented minds. The two former colleagues' rivalry would propel them to taking command of a market in its infancy.

Sinclair's masterstroke was to focus on reducing costs for its new machine, the ZX Spectrum, to allow it to be available to buy for around £100. Released in 1982, suddenly the new item everybody was talking about was also universally affordable. A generation of "Speccy" programmers was born.

That same year, Acorn competed by securing a coveted BBC license for their new system. With Auntie and the newly elected Margaret Thatcher's approval, one of Curry's machines was pledged to every school in the country. Sales went through the roof. Their BBC Micro, made initially for an expected sales run of 12,000, went on to sell 1.5m units. Many could still be found in schools around the country in the late 1990s.

These new must-have items for a brief time held a unique position in the national consciousness. News reports and magazines were full of stories on these new and exciting technologies. With computers affordable, accessible, and getting more and more sophisticated, it seemed like anything was possible.

Acorn and Sinclair's period at the top was short-lived, however, as the home computer market crashed in 1984, taking the two companies with it. Sinclair was eventually sold to Amstrad, Acorn to Olivetti, and neither ever managed to again make such an impact on the home computer marketplace.

Sinclair's and Curry's lasting legacy is unquestionable. The acceptance of the idea of playing "computer games" as a relaxing solo pastime in the UK was thanks largely to those initial systems. The belief of a personal computer as being an item every home should have another.

The ARM chip created by Acorn has also left a lasting imprint, having gone on to be the most used microchip in modern electronics. The phone you have in your pocket almost certainly has one in it – a design based around that made by the same Cambridge boffins that created the BBC Micro back in 1983. An incredible 10bn have been produced.

We also have Acorn and Spectrum to thank for many of the current generation of British programmers. The Spectrum and Micro were the first widely available systems to capture the imagination of inquisitive would-be-programmers – and opened up for the first time the possibility of a earning a living by making games. Chuckie Egg and Jet Set Willy were both created using these platforms.

With such a firm grip on the market, the question has to be asked – could they have hung on? You could argue of course that the strength of the Apples and IBMs of the time were inexorable forces that were always destined to take control of the industry – nevertheless, Acorn's and Sinclair's collapses from two of Britain's leading computer companies to near dissolution in five years has to be attributed somewhere.

For Sir Clive, of course, you could perhaps blame the doomed Sinclair C5 – an electric buggy which was supposed to reinvent modern transport but ended up selling a mere 12,000 units. His belief that every person in the country would want one was hopelessly misguided. Curry perhaps took his eye off the ball, assuming that demand would continue to grow. Neither managed to successfully enter foreign markets. But ultimately, both were victims of there own success. By 1983, every person who wanted a "microcomputer" had one. And with no marketable leap in processing power or new selling point, the bottom was always going to fall out of the market.

Micro Men ends on a poignant note as Sinclair, riding his C5, is overtaken by two hulking articulated lorries, labelled Microsoft and Apple. Perhaps it's foolish to think that two small Cambridge-based companies could ever keep up. But it's important not to forget that, for a few months at least, they managed to poke their noses in front.

•Micro Men screens on BBC4 tonight at 9pm. Jack Arnott attended a special preview screening at Bafta.